表界面化学在材料研究中的应用

表界面化学一直是人们研究的重要方向,本文综述了表界面化学知识在无机材料及复合材料中的应用,尤其近些年又一突破性的进展——在军工方面中的应用,总结了一些研究材料表界面的现代分析方法。研究表界面化学知识不仅对人们的生产、生活具有重要的意义,而且还对军工研究具有重要指导意义。     

可控设计的Co-N/C电催化剂及其氧还原反应活性

能源问题是事关国家发展和安全的重大问题,氧还原反应作为燃料电池阴极半反应近年来成为能源和电催化领域的研究热点之一。通过利用2,9-二甲基-1,10-邻菲啰啉与钴离子的配位形成配合物,将该配合物与炭黑混合均匀,经过中温热解和浓硝酸氧化后得到钴、氮表面修饰的碳负载纳米催化剂Co-N/C。实验首先利用旋转圆盘电极和旋转环盘电极(RRDE)考察了催化剂在不同pH值下的电催化氧还原性能。电化学测试结果表明,在碱性条件下,该催化剂具有与商业Pt/C相近的4电子氧还原催化性能。随后,通过SEM、TEM、XPS、XRD和FT-IR等设备对催化剂进行表征,以揭示Co-N/C催化剂4电子氧还原催化活性增强的来源。运用功能化修饰策略调控碳材料表面的催化活性位点和碳的电子结构,克服了本征碳材料催化活性不高的缺陷,为设计新型非贵金属氧还原反应催化剂提供了一种新的思路。     

氧化锰电催化析氧反应及其电极界面特性

析氧半反应是速控步骤。氧化锰（MnO_x）具有多价态,可形成多个子步骤降低活化能。二氧化钛（TiO₂）是抗氧化性半导体。考察两种氧化锰催化剂析氧性能,即滑动弧等离子体合成MnO_x（pM）和商业化（cM）,与商业化TiO₂ （cT）比较。通过理想极化电极系统（IPE）解析,表达电极界面特性,揭示三相界面与活性的关联。结果表明：对两种MnO_x 催化剂,pM比cM性能更优。碱性环境中,前者起始电位低180 mV,Tafel斜率近半。酸性中,均表现阶跃式极化,析氧性能相近。cM比cT催化剂析氧性能更优,起始电位低420 mV。溶液电阻R_s与活性变化趋势一致。对相同催化剂,考察I/C、担量、单双层结构,电容压降占比f_Cd与活性一致。对不同催化剂,考察cM, cT或pM, cM,f_Cd与活性不一致,这与多价态锰参与非法拉第过程有关。     

含氢硅油改性聚醚破乳剂的表界面性能研究

将聚醚破乳剂SP169、AP201和AE1910进行硅油改性获得改性破乳剂SISP、SIAP和SIAE,并通过红外光谱进行了结构表征.测定了上述破乳剂的表面参数cmc、γcmc、Γmax、Amin,结果显示改性后的破乳剂表面张力更低.动态油/水界面张力研究结果显示,多支化的SIAP和SIAE其降低油/水界面张力的能力更...     

一体式再生燃料电池双效氧电极催化剂

对一体式可再生燃料电池双效氧电极催化剂进行研究,考察了析氧催化剂和贵金属Pt黑组成的复合催化剂的双效性能以及催化剂配比和焙烧温度对性能的影响,用XRD对催化剂的物相特性进行表征。结果表明：复合催化剂的燃料电池性能按以下顺序递减：Pt黑＞Pt/Ru/Ir＞Pt/Ru＞Pt/IrO2～Pt/Ir＞Pt/RuO2;水电解性能按以下顺序递减：Pt/IrO2＞Pt/RuO2＞Pt/Ir＞Pt黑。分析比较,Pt/IrO2复合催化剂表现出良好的燃料电池/水电解双功能特性以及循环稳定性,具有最佳的URFC能量转换效率。因此,Pt/IrO2复合催化剂是最适宜的双效氧电极催化剂。一定温度范围内的焙烧处理对Pt/IrO2催化剂燃料电池性能影响不大,而对水电解性能具有一定的影响,大电流密度运行,未焙烧处理的Pt/IrO2催化剂表现出更好的水电解性能。     

Na-Fe_3O_4/ZSM-5催化剂上CO_2加氢反应汽油烃产物的组成调控

CO_2加氢直接合成汽油不仅有利于CO_2减排,还可减轻人们对化石能源的依赖。汽油馏分烃产物组成是决定汽油燃料品质的重要因素,其调控是该过程具有挑战性的研究热点。研究NaFe_3O_4/ZSM-5催化剂中分子筛的金属(La,Ga,Zn,Cu,Co)改性对CO_2加氢产物中汽油馏分烃组成的影响,结果表明,与其他金属相比,Cu改性ZSM-5分子筛组分可在保持较高汽油收率前提下,明显提高汽油产物中异构烷烃选择性。优化改性分子筛中Cu质量分数8%时,汽油馏分烃产物中异构烷烃含量最高。当Na-Fe_3O_4和Cu-ZSM-5采用分层填装方式时,汽油馏分烃产物中异构烷烃含量达50.5%,组成调控后富含异构烷烃汽油产品更符合汽油品质升级趋势需求。     

金属有机框架在电解水反应中的研究进展

金属有机框架(简称MOFs)是一类具有立体框架结构的多孔配位聚合物,它是由有机配体通过配位键连接无机金属簇组装形成的,由于具有可调节的孔道结构、较大的比表面积以及拓扑结构多样性等优点,MOFs在电解水领域显示出巨大的潜力。从电解水反应的基本原理入手,综述了近年来MOFs材料在电解水领域中的研究进展,重点介绍了MOF基电催化剂设计相关的策略,最后提出了MOFs材料在合成和应用方面面临的问题和挑战,并对这类材料未来的发展趋势进行了展望。     

碳纤维/环氧复合材料界面优化研究进展

从界面粘合理论、碳纤维表面改性、树脂基体改性等方面对碳纤维/环氧复合材料界面性能的研究进展进行了综述。表明界面对碳纤维/环氧复合材料充分发挥其优异性能起关键作用,其界面优化设计主要从碳纤维表面改性和树脂增韧改性入手,研究已取得一定进展;但亟需在界面作用机理、界面改善处理的工业化生产、纳米材料改性的技术难题等方面期待突破。     

基于表/界面调控的金属氧化物半导体光催化剂的理性构筑

近年来半导体光催化作为一种绿色技术在解决环境问题和提供可再生能源方面获得了广泛关注,然而较低的催化效率限制着它的实际应用。合理设计金属氧化物半导体的表/界面结构,是提升光催化剂性能的有效手段。对近年来半导体光催化剂的表/界面结构调控以及构-效关系的研究进行了梳理,介绍了在单一组分体系中利用晶面效应优化光催化性能的可行措施。在此基础上,总结了晶面/界面结构调控在复合光催化剂体系中的应用。最后,总结了该领域面临的挑战与未来的前景。     

Recent advances in cardiovascular stent for treatment of in-stent restenosis:Mechanisms and strategies

Treatments of atherogenesis,one of the most common cardiovascular diseases (CVD),are continuously being made thanks to innovation and an increasingly in-depth knowledge of percutaneous transluminal coronary angioplasty (PTCA),the most revolutionary medical procedure used for vascular restoration.Combined with an expanding balloon,vascular stents used at stricture sites enable the long-time restora-tion of vascular permeability.However,complication after stenting,in-stent restenosis (ISR),hinders the advancement of vascular stents and are associated with high medical costs for patients for decades years.Thus,the development of a high biocompatibility stent with improved safety and efficiency is urgently needed.This review provides an overview of current advances and potential technologies for the modi-fication of stents for better treatment and prevention of ISR.In particular,the mechanisms of in-stent restenosis are investigated and summarized with the aim to comprehensively understanding the patho-genesis of stent complications.Then,according to different therapeutic functions,the current stent mod-ification strategies are reviewed,including polymeric drug eluting stents,biological friendly stents,pro-healing stents,and gene stents.Finally,the review provides an outlook of the challenges in the design of stents with optimal properties.Therefore,this review is a valuable and practical guideline for the devel-opment of cardiovascular stents.     

Toughening and reinforcement of HDPE/CaCO3 blends by interfacial modification—interfacial interaction

To improve the mechanical properties and structure of HDPE/CaCO₃ composites, a type of modifier, consisting mainly of carboxylated polyethylene (CPE), and a type of CaCO₃ grafted with acrylamide (CaCO₃(SINGLE BOND)A) were used. The carboxyl group content of CPE was from 1 to 10%. The amide group content on the surface of the modified CaCO₃ was from 0.2 to 1.8%. The interfacial structure and interaction of ternary blends of HDPE, CPE, and CaCO₃(SINGLE BOND)A were studied. The results indicate that the higher the amide group content and the carboxyl group content, the higher the tensile and impact strength. This behavior has been attributed to a series of chemical and physico-chemical interactions taking place between the two components during the blending process which were confirmed by FTIR and extraction experiments. The improvement of interfacial adhesion by the CPE and CaCO₃(SINGLE BOND)A was also clearly revealed in the SEM of the fracture surface. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1275–1281, 1997     

制备聚酰胺复合膜中界面聚合反应添加剂研究进展

聚酰胺复合膜以其优良的稳定性及良好的分离选择性成为水处理和化工分离领域应用范围最广的分离材料之一。聚酰胺复合膜一般采用界面聚合法制备,由于界面聚合反应活性高、反应参数多,致使界面层结构难以控制,膜的渗透性或选择性不理想。因此,如何有效调控膜结构,实现膜的高渗透性或选择性是目前面临的重要挑战。近期诸多研究表明,在水相或有机相中引入添加剂可以改变油水界面张力进而调控单体界面扩散速率及界面分布,或通过改变反应机理影响聚合反应速率,最终实现对界面层结构和膜性能的调控。本文从添加剂种类、性质和调控作用等角度总结了近年来添加剂对复合膜结构及性能调控的研究进展,分析了现有研究存在的问题,并建议从微观层面探究界面过程的物理化学性质以及开发高时间分辨率原位表征方法等。     

界面聚合在渗透汽化膜分离领域的应用进展

蒸馏、萃取等传统分离方法能耗高,污染环境,而渗透汽化由于低能耗、高效、环保等优势,为共沸物、近沸点混合物的分离提供了新的思路,但渗透汽化膜制备过程中面临的最大问题是获得性能优异且稳定的膜材料。在众多制备方法中,界面聚合法具有反应活性高、常温下生成膜层稳定、制备活性层致密等特点而备受关注。通过对界面聚合过程的调控,可以优化活性层,从而制备出兼具高通量和高选择性的渗透汽化膜。本文综述了界面聚合的原理、在渗透汽化膜制备方面的优势和近年来国内外的研究进展,详细阐述了复合膜制备过程中底膜的选择与改性、界面聚合条件的调控对渗透汽化膜结构和分离性能的影响机制,并对界面聚合制备渗透汽化膜所面临的问题及前景进行了总结与展望。     

Recent advances in the preparation of functionalized polysulfones

This review summarizes the studies related to chemical functionalization of polysulfones used in many different applications such as membranes with special functions, nanocomposites, biofilm formation, fuel cells etc. reported in recent years from the literature since 2000. Various strategies have been applied for the functionalization of polysulfones. One strategy is to add desired functionality into starting monomers in the solution containing the main components of commercial polysulfones, the aromatic dihalide sulfone and bisphenol monomers, or to functionalize the related monomers before the condensation. Another approach is to form difunctional polysulfone oligomers. Then, functional groups can be utilized to react with monomers or other polymers to obtain functional polymers or block copolymers. The most applied method is post‐modification of commercially available polysulfones by incorporation of functional groups to their aromatic groups and their use in the formation of graft polymers or polysulfone‐based networks. © 2013 Society of Chemical Industry     

Changes in the interfacial properties of PC/SAN blends with compatibilizer

Block copolymers of polycarbonate‐b‐poly(methyl methacrylate) (PC‐b‐PMMA) and tetramethyl poly(carbonate)‐b‐poly(methyl methacrylate) (TMPC‐b‐PMMA) were examined as compatibilizers for blends of polycarbonate (PC) with styrene‐co‐acrylonitrile (SAN) copolymer. To explore the effects of block copolymers on the compatibility of PC/SAN blends, the average diameter of the dispersed particles in the blend was measured with an image analyzer, and the interfacial properties of the blends were analyzed with an imbedded fiber retraction (IFR) technique and an asymmetric double cantilever beam fracture test. The average diameter of dispersed particles and interfacial tension of the PC/SAN blends were reduced by adding compatibilizer to the PC/SAN blends. Fracture toughness of the blends was also improved by enhancing interfacial adhesion with compatibilizer. TMPC‐b‐PMMA copolymer was more effective than PC‐b‐PMMA copolymer as a compatibilizer for the PC/SAN blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2649–2656, 2003     

Effects of oil phase viscosity on interfacial tension behaviour of oil/alkaline systems as measured by the spinning drop tensiometer

This note examines the effects of oil phase viscosity on the interfacial tension of reacting systems (acidic crude oils in contact with alkaline solutions) as measured by the Spinning Drop Tensiometer. Surfactants are produced by chemical reactions at the interface, thereby causing the shape of the oil droplet in the tensiometer to change continuously. The rates of droplet elongation/contraction are necessarily influenced by the oil phase viscosity, thereby affecting directly the measured interfacial tension. The principal conclusion of this work is that although oil phase viscosity exerts a significant effect on the dynamic interfacial tension after attainment of the minimum value, it makes for only a small absolute change in the magnitude of the minimum interfacial tension itself.     

煤化学链燃烧载氧体研究进展

煤的化学链燃烧是清洁煤燃烧的重要技术之一。化学链中载氧体的使用可以避免煤和空气直接接触,从而避免氮氧化物等污染物的产生并提高能量转化效率。一般来说,煤的化学链燃烧有2种反应途径:煤气化化学链燃烧和氧解耦化学链燃烧;不同反应途径将极大影响载氧体组分以及结构设计。详细论述了2015-2020年煤化学链燃烧中固态金属载氧体的研究进展,包括铁基、锰基、铜基、镍基、硫酸钙以及其他复合金属载氧体。总结了不同金属载氧体的优缺点、反应路径、气-固和固-固反应机理、金属与载体的相互作用以及载氧体失活原理。铁基载氧体被广泛应用于气化化学链燃烧中,但单一铁基载氧体的反应速率较低。适量添加碱金属或碱土金属可以提升载氧体的反应活性。锰基载氧体在化学链燃烧中具有两面性:一方面可以在高温缺氧气氛中释放气态氧,另一方面也可以与还原性气体发生气-固反应。通过使用惰性载体以及碱金属添加剂可以提高锰基载氧体的机械强度和氧解耦能力。含铜载氧体具有出色的氧解耦能力和反应活性而被广泛关注,然而铜及其氧化物低熔点所带来的金属聚集导致载氧体的失活问题亟需克服。研究发现使用铁、锰和铜矿石制得的载氧体具有良好的反应性能。硫酸钙载氧体具有较好的反应活性,但煤的化学链燃烧时潜在的二氧化硫和硫化氢副产物需要引起重视。镍基载氧体虽然在煤的化学链燃烧中反应性能较好,但硫毒化、成本较高和环保性能不佳等缺点导致近年来镍基载氧体的研究较少。新型双金属或多金属载氧体可以同时结合2种金属的反应特性,从而显著提高载氧体的整体反应活性。基于载氧体的研究现状,对未来的发展方向提出了4点建议:结合2种煤的化学链燃烧机理设计新型氧解耦辅助化学链燃烧载氧体;发展新型材料和金属组分的载氧体;利用冶金工业废料制得载氧体;开发新型结构的载氧体。     

A dynamic mechanical analysis of the interfacial changes induced from both the reinforcement and the matrix sides in polypropylene/surface modified talc composites

The interfacial changes associated with a series of polypropylene based composite materials with modified interphases from the reinforcement side, from the matrix side and both were studied by following their dynamic mechanical behavior. Composites consisted in an isotactic polypropylene (iPP) matrix, a series of talc with different surface functionalities (hydroxyl, chloride, n‐butyl amine, and silanes) and a commercial interfacial agent form the matrix side (iPP‐SA with 5% of grafts). A comprehensive interpretation of the link existing between the dynamic mechanical responses of the series of 75/25 iPP/talc composites and the molecular relaxation spectrum occurring in the polymer phase of the composites is made with emphasis on the role played by the interfacial modifications performed from each and both sides of the interphase. Dynamic mechanical analysis has been used here to study how the intended interfacial modifications affected the behavior of the composites. The efficiency of the interfacial phenomena is discussed from a phenomenological point of view as well as by considering classical criteria such as the glass transition temperature and the glass to rubbery transition. Finally, a correlation between mechanical parameters from the microscopic scale and others from the macroscopic scale appears to emerge. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42678.